Fiber modified layer and methods of making and using same

ABSTRACT

A composition for use in a fiber modified layer, comprising an aggregate material, a binder, and a plurality of fibers, wherein each fiber has a length of greater than 0.25 inches. Also provided is a method of selecting a fiber modified layer for applying on an existing surface, comprising the steps of: providing a binder mixture having an effective amount of an aggregate material, a binder, and a plurality of fibers, wherein each of the plurality of fibers has a length greater than 0.25 inches; applying the binder mixture to a selected surface to form a fiber modified proposed layer; testing the fiber modified proposed layer for fatigue or crack resistant properties; and selecting the binder mixture for application on the existing surface for performance if the fiber modified proposed layer has fatigue or crack resistant properties.

CROSS REFERENCE

This application is a divisional application of U.S. patent applicationSer. No. 12/252,729 filed Oct. 16, 2008 now U.S. Pat. No. 7,897,254.

FIELD OF THE INVENTION

This invention relates generally to paved surfaces, and moreparticularly, not by way of limitation, to a fiber modified layer havingimproved fatigue or crack resistant properties.

DESCRIPTION OF THE RELATED ART

One of the most adaptable tools in road maintenance is slurry mixture.Slurry mixture is a polymer-modified cold-mix paving system that canremedy a broad range of problems on today's streets, highways, andairfields. Slurry mixture begins as a mixture of dense-graded aggregate,asphalt emulsion, water, additives, recycled materials, and mineralfillers. While conventional slurry seal is used around the world as aneconomical treatment for sealing and extending the service life of bothurban and rural roads, slurry mixture has added capabilities, due to theuse of high-quality, carefully monitored materials, including advancedpolymers and other modern additives. Slurry mixture is recognized as acost-effective way to treat surface wheel-rutting problems and a varietyof other road surface problems. Slurry mixtures are hereafter referencedonly as slurry mixture.

Slurry mixture is made and applied to existing pavements by aspecialized machine, which mixes the components on site, and spreads themixture onto the road surface. Materials are continuously and accuratelymeasured, and then thoroughly combined in the slurry mixture machine'smixer. As the machine moves forward, the mixture is continuously fedinto a variable-width “surfacing” box which can apply materials to thewidth of a traffic lane in a single pass. Alternately, speciallyengineered “rut” boxes, designed to deliver the largest aggregateparticles into the deepest part of the rut to give maximum stability inthe wheel path, may be used. Edges of the slurry mixture areautomatically feathered. The new surface is initially a dark brown colorand changes to the finished black surface as the water is ejected andthe surface cures, permitting traffic within one hour in most cases.Continuous-load pavers utilize support units that bring the materials tothe job site and load the machine while it is working, thus maximizingproduction and minimizing transverse joints.

Because slurry mixtures can be effectively applied to most surfaces,more area is covered per ton of mix, resulting in cost-effectivesurfacing. Traditional hot mix used approximately 165 lbs to 220 lbs ofmixture to apply a 1.5 inch to 2 inch layer over a 1 square yard area.Conversely, slurry mixtures typically use 15 lbs to 30 lbs of mixtureper square yard to provide a suitable surface. Slurry mixtures alsocreate a new, stable surface that is resistant to rutting and shoving insummer. The mixture fills in cracks and surface imperfections. Becauseof its quick-traffic properties, slurry mixture can be applied in abroad range of temperature and weather conditions, effectivelylengthening the paving season.

Slurry mixture begins with the selection of high-qualitymaterials—asphalt emulsion, aggregate, emulsifiers, water, andadditives—which must pass special laboratory tests, both individuallyand when combined, as a slurry mixture system. The International SlurrySurfacing Association's (ISSA) broad range of specialized mix designtests help to insure that the mixture has the desired slurry mixturecharacteristics.

To this end, although slurry mixture as currently practiced is anefficient road maintenance process, further improvements are desirableto a process for enhancing the fatigue resistant properties of pavedsurfaces. It is to such a fiber modified layer and method of selectionand use that the present invention is directed.

Fibers have been used to enhance the crack resistance of paved layerslike slurry seal and slurry mixture. The known art used a variety offibers ≦0.25 inches in length to enhance the crack resistant propertiesof the layer. When tested for crack resistance like the ISSA FlexuralBend Test crack resistance was enhanced by using fibers.

While fatigue resistance, fracture energy, and fracture toughness of themixture can be somewhat enhanced by ≦0.25 inch fibers, surprisinglycrack resistance is generally unaffected.

Literature is laden with grid, mat, and lattice systems to assist crackresistance in road construction and rehabilitation. These processes havemany drawbacks. They are expensive, require an extraordinary amount offiber type materials and are difficult to construct.

Accordingly, it is desirable to provide a fiber modified layer withenhanced fatigue and crack resistant properties.

SUMMARY OF THE INVENTION

In general, in a first aspect, the present invention relates to a methodof selecting a fiber modified layer for applying on an existing surface,comprising the steps of: providing a binder mixture having an effectiveamount of an aggregate material, a binder, and a plurality of fibers,wherein each of the plurality of fibers has a length greater than 0.25inches; applying the binder mixture to a selected surface to form afiber modified proposed layer; testing the fiber modified proposed layerfor fatigue or crack resistant properties; and selecting the bindermixture for application on the existing surface if the fiber modifiedproposed layer has fatigue or crack resistant properties.

The aggregate material may be mineral aggregates, such as sand, stone,lime, Portland cement, kiln dust, or mixtures thereof man madeaggregates, such as wet bottom boiler slag, blast furnace slag, ormixtures thereof, recycled materials, such as reclaimed asphaltpavement, glass, ground rubber tires, ceramics, metals, or mixturesthereof; or mixtures thereof. The binder may be an asphalt emulsion, hotasphalt cement, hot polymer modified asphalt cement, petroleum solventcutback asphalt, polymer modified petroleum solvent cutback asphalt,resinous hydrocarbons, emulsified resinous hydrocarbons, emulsifiedpolymer modified resinous hydrocarbons, or mixtures thereof. If thebinder is an asphalt emulsion, it may be elastomer modified or polymermodified, and the polymer may be natural latex, SBR latex, or neoprenelatex and the like. The plurality of fibers may be synthetic fiber,glass fiber, metallic fiber, steel fiber, boron fiber, aluminum fiber,acrylic fiber, nylon fiber, rayon fiber, polyester fiber, polystyrenefiber, cellulose acetate fiber, acetate base fiber, polypropylene fiber,polyacrylamide fiber, polyethylene fiber, carbon fiber, aramid fiber, ormixtures thereof. The fibers may each have a length of greater than 0.25inches. The binder mixture may further comprise one or more additives,including adhesion promoters, surfactants, polymers, cross-linkingagents, vulcanization agents, accelerators, extenders, or fluxingagents.

Testing the fiber modified proposed layer for crack resistant propertiesmay further comprise using a Texas Overlay test. Testing may furthercomprise using a modification of TxDOT Test Method T-248-F. The fibermodified proposed layer may be determined to have fatigue or crackresistant properties if testing results in a number of cycles to failuregreater than 3 where displacement is 0.05 inches, cycle time is 60seconds, and temperature is 5° Celsius. The fiber modified proposedlayer may also be tested using flexibility tests, bending tests, orfracture energy and fracture toughness tests, such as the Flexural Bendtest, ISSA TB146 or the Disk-shaped Compact Tension Test, ASTM D7313-07.

The method of selecting a fiber modified layer for applying on anexisting surface may further comprise applying the selected fibermodified proposed layer having crack resistant properties to theexisting surface. The existing surface may have a direction of travel,and the method may further comprise preferentially aligning theplurality of fibers in the binder mixture in the direction of travel.

In general, in a second aspect, the present invention relates to acomposition for use in a fiber modified layer, comprising an aggregatematerial, a binder, and a plurality of fibers, wherein each fiber has alength of greater than 0.25 inches. The composition may further compriseone or more additives.

The aggregate material may be mineral aggregates, such as sand, stone,lime, Portland cement, kiln dust, or mixtures thereof; man madeaggregates, such as wet bottom boiler slag, blast furnace slag, ormixtures thereof; recycled materials, such as reclaimed asphaltpavement, glass, ground rubber tires, ceramics, metals, or mixturesthereof; or mixtures thereof. The binder may be an asphalt emulsion, hotasphalt cement, hot polymer modified asphalt cement, petroleum solventcutback asphalt, polymer modified petroleum solvent cutback asphalt,resinous hydrocarbons, emulsified resinous hydrocarbons, emulsifiedpolymer modified resinous hydrocarbons, or mixtures thereof. If thebinder is an asphalt emulsion, it may be elastomer modified or polymermodified, and the polymer may be natural latex, SBR latex, or neoprenelatex. The plurality of fibers may be synthetic fiber, glass fiber,metallic fiber, steel fiber, boron fiber, aluminum fiber, acrylic fiber,nylon fiber, rayon fiber, polyester fiber, polystyrene fiber, celluloseacetate fiber, acetate base fiber, polypropylene fiber, polyacrylamidefiber, polyethylene fiber, carbon fiber, aramid fiber, or mixturesthereof. The fibers may each have a length of greater than 0.25 inches.Each of the additives may be adhesion promoters, surfactants, polymers,cross-linking agents, vulcanization agents, accelerators, extenders, orfluxing agents.

The composition may demonstrate fatigue or crack resistant propertieswhen tested using a Texas Overlay test. Testing may further compriseusing a modification of TxDOT Test Method T-248-F. The composition maybe determined to have fatigue or crack resistant properties if suchtesting results in a number of cycles to failure greater than 3 wheredisplacement is 0.05 inches, cycle time is 60 seconds, and temperatureis 5° Celsius. The composition may also be tested using flexibilitytests, bending tests, or fracture energy and fracture toughness tests,such as the Flexural Bend test, ISSA TB146 or the Disk-shaped CompactTension Test, ASTM D7313-07.

The composition may be such that the application of the composition toan existing surface results in the preferential alignment of theplurality of fibers. Further, where the existing surface has a directionof travel, the application of the composition to the existing surfacealong the direction of travel may result in the preferential alignmentof the plurality of fibers along the direction of travel.

Finally, in a third aspect, the present invention relates to a fibermodified layer comprising a binder mixture having an effective amount ofan aggregate material, a binder, and a plurality of fibers, wherein eachof the plurality of fibers has a length greater than 0.25 inches, andwhere the binder mixture has been applied to an existing surface. Theexisting surface may have a direction of travel, and the binder mixturemay be applied to the existing surface along the direction of travel.The plurality of fibers may be preferentially aligned in the directionof travel. The preferentially aligned plurality of fibers may providefatigue or crack resistant properties to the fiber modified layer. Theseproperties may be demonstrated through testing.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph showing the results of the Texas Overlay Tester.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The devices and methods discussed herein are merely illustrative ofspecific manners in which to make and use this invention and are not tobe interpreted as limiting in scope.

While the devices and methods have been described with a certain degreeof particularity, it is to be noted that many modifications may be madein the details of the construction and the arrangement of the devicesand components without departing from the spirit and scope of thisdisclosure. It is understood that the devices and methods are notlimited to the embodiments set forth herein for purposes ofexemplification.

In the present invention, a composition for a pavement layer isprovided. The composition may include an asphalt emulsion, aggregatematerial, and a plurality of fibers wherein each of the plurality offibers has a length greater than 0.25 inches. A method for applying asurface is also provided. The method may comprise adding a sufficientamount of recycled materials, mineral fillers, and water to an aggregateof suitable quality. The components are mixed thoroughly. Fibers ofsuitable quality are added and mixed into the system. Finally, binder isstirred into the mixture and it is immediately applied. The applicationof the mixture preferentially aligns fibers greater than 0.25 inchessubstantially perpendicular to transverse cracks thereby increasing theresistance to cracking and fatigue.

The fiber modified layer has crack resistant, fatigue resistantproperties with enhanced fracture energy and fracture toughness disposedon an existing surface. Broadly, the fiber modified layer may include aneffective amount of a fiber modified mixture of a binder, aggregate,additives, and a plurality of fibers.

The binder contains bitumen (asphalt) and other additives suitable foruse in bituminous binders, such as adhesion promoters, surfactants,polymers, cross-linking agents, vulcanization agents, accelerators,extenders, fluxing agents, and the like. The additives used forfabricating the binder are selected based on the desired properties ofthe binder for a given application of the fiber modified layer.

Polymer-modified or elastomer-modified binders may be used. Suitableelastomers are described in but not limited to U.S. Pat. No. 4,242,246,issued to Maldonado et al. on Dec. 30, 1980, the entirety of which ishereby incorporated herein by reference. Suitable polymer cross-linkingtechnologies that can be utilized are described in but not limited toU.S. Pat. No. 4,330,449, issued to Maldonado et al. on May 18, 1982, theentirety of which is hereby incorporated herein by reference. Inaddition, binders as described in U.S. Pat. No. 6,830,408, issued toBlankenship et al. on Dec. 14, 2004, the entirety of which is herebyincorporated herein by reference, may be used. Additionally, latexproducts like natural latex, SBR latex, neoprene latex, and the like aresuitable polymers. Polymer loadings may be greater than 0.5% up about20% based on the weight of the binder. Additionally, all polymers arenot water soluble.

The binder may be in the form of an asphalt emulsion or a polymermodified asphalt emulsion. In other embodiments, the binder may be hotasphalt cement, hot polymer modified asphalt cement, petroleum solventcutback asphalt, polymer modified petroleum solvent cutback asphalt,resinous hydrocarbons, emulsified resinous hydrocarbons, emulsifiedpolymer modified resinous hydrocarbons, and the like.

The aggregate of the fiber modified layer provides support and structureto the fiber modified layer to resist cracking, fatigue, and rutting.The aggregate may be sized and shaped so as to provide sufficientstructure and support thereby resisting the formation of ruts in thefiber modified layer and may be blended to various gradedspecifications. Examples of aggregate may include, but are not limitedto, mineral aggregates, such as sand, stone, lime, Portland cement, kilndust, and combinations thereof and may be crushed or rounded, highquality coarse and fine. Other suitable aggregates are man madeaggregates like wet bottom boiler slag, blast furnace slag, and thelike. Alternately, recycled materials like reclaimed asphalt pavement(RAP), glass, ground rubber tires, other ceramics, metals, and the likecan be substituted in part or in whole for the aggregate and isgenerally considered as aggregate. It should be understood andappreciated that the aggregates used in accordance with the presentinvention may be any suitable material known in the art for use asaggregates in asphalt paving applications. The aggregate may be added tothe fiber modified layer in any amount sufficient to provide support andstructure to the fiber modified layer to resist cracking, enhancefatigue properties, and maintain stability of the fiber modified layer.

The ISSA (International Slurry Surfacing Association) is the commonlyknown industry leader for slurry mixture and slurry surfacingapplications throughout the world. The ISSA has an industry minimumstandard for aggregate cleanliness of 65%. Aggregate cleanliness, orsand equivalent value, for aggregate is typically above 80%. Sand istypically not added to aggregate, but embodiments exist where sand isadded. In one embodiment, although sand is not added to aggregate,crushing of the limestone or other minerals for aggregate follows thegradation detailed, and generally is considered to be “sand” since it istypically close to meeting most sand specifications as well as the sandequivalent value of soils and fine aggregate test.

The plurality of fibers of the present invention may be any such fiberutilized in the surfacing process. Examples of synthetic fibers include,but are not limited to, glass fiber, metallic fiber such as steel fiber,which includes boron fiber and aluminum fiber, acrylic fiber, nylonfiber, rayon fiber, polyester fiber, polystyrene fiber, celluloseacetate fiber, acetate base fiber, polypropylene fiber, polyacrylamidefiber, polyethylene fiber, carbon fiber, and aramid fiber. Each of theplurality of fibers has a length greater than 0.25 inches. Fibers longerthan 0.25 inches provide enhanced crack resistance and, when appliedwith a suitable “surfacing” box, the fibers will preferentially alignsubstantially perpendicular to transverse cracks increasing theresistance to cracking and fatigue.

Additives are incorporated in a suitable manner and in sufficientquantities to control consistency and other properties of the mixture.These additives consist of but are not limited to Portland cement,mineral fillers, recycled materials, sodium sulfates, calcium sulfates,water, surfactants, breaking agents, coating agents, and the like.

Various mixtures may be created when forming the fiber modified layer.Different proportions of different binders, different binder amounts,different binder concentrations, different fibers, different fiberamounts, different lengths of fibers, and various aggregate gradationscan be formed to increase fatigue and fracture resistance. The crackresistant mixture formed has the physical properties and performancecharacteristics to make a crack resistance layer that has good fatigueresistance.

The fiber modified layer can be fabricated such that it has apredetermined level of fatigue resistance. The fatigue resistance of thefiber modified layer can be determined by measuring the number of cyclesto failure of a test specimen of the fiber modified layer when subjectedto suitable strains. Measurements of fatigue resistance include but arenot limited to Flexural Beam Fatigue Test AASHTO T321-03 or D7460-08, orthe TX Overlay Tester TxDOT T-248-F.

A fatigue-resistant layer of a road may be created from the bituminousmixture of the present invention. The bituminous mixture can be used forvarious paving applications, such as to make under layers, interlayers,and overlays. Such layers have the ability to retard the formation andseverity of reflective cracks and to increase fatigue resistance.

The mixture can be tested for its resistance to cracking using a crackresistance test. The crack resistance test can be any type of test formeasuring the resistance of the mixture to cracking. Examples of crackresistant tests include, but are not limited to, flexibility tests,bending tests, fracture energy and fracture toughness tests, and thelike. An example of a bending test is the Flexural Bend test (ISSATB146). An example of a fracture energy or fracture toughness test isthe Disk-shaped Compact Tension test [DC(T)] ASTM D7313-07. An exampleof a cracking test is the Texas Overlay test (TxDOT T-248-F). It shouldbe understood and appreciated that any test known in the art capable ofdetermining the cracking resistance, fracture energy, or fracturetoughness of the mixture can be implemented in accordance with thisinvention.

The enhanced cracking and fatigue resistance of the fiber modified layeris due to the orientation of the fiber in the mixture relative to anypreexisting or future crack in the surface. The ligament bridges thecrack gap and provides enhanced fatigue and crack resistance.

The specialized machine that mixes the materials in place also appliesthe product to the surface. The machine spreads the mixture onto thesurface using a suitable spreading device. The specialized machine mayapply the slurry mixture longitudinally to the normal direction oftraffic. In this embodiment, the combination of the direction of travelof the specialized machine and the suitable spreading devicepreferentially aligns fibers of sufficient length in the direction offorward movement. Suitable fibers are preferentially alignedsubstantially perpendicular to transverse cracks enabling enhanced crackand fatigue resistance. In another embodiment, the fibers are randomlyaligned in the mixture that is applied to the surface. Fiber lengthsgreater than 0.25 inches provide sufficient ligaments that cross theexisting or future cracks enabling enhanced fatigue and crackresistance.

The application of the bituminous fiber mixture can be achieved with anysuitable “surfacing” box that applies the bituminous fiber mixture to asurface. Preferably, the surfacing box applies the bituminous fibermixture whereby the direction of travel is substantially perpendicularto transverse crack and preferentially orients the fibers in thedirection of travel. The surfacing box can be but is not limited toequipment such as asphalt pavers made by Barber Greene or Blaw-Knox,drag boxes similar to U.S. Pat. No. 7,108,450 to Grubba, spreader boxessimilar to U.S. Pat. No. 6,398,453 to Stegemoeller, paving machinessimilar to U.S. Pat. No. 6,079,901 to Banks, and the like.

In a further embodiment of the present invention, a method of selectinga mixture of the fiber modified layer is provided. A mixture, such asthat described herein, is selected for fabricating the fiber modifiedlayer according to one or more of the tests described above.

In order to further illustrate the present invention, the followingexample is given. However, it is to be understood that the example isfor illustrative purposes only and are not to be construed as limitingthe scope of the subject invention:

EXAMPLE

The binder was an asphalt emulsion using a base asphalt of PG64-22,Ralumac® slurry mixture chemistry at a suitable pH and about 3.75%natural latex based on the weight of the asphalt.

The aggregate was a chat aggregate from Bingham Sand and Gravel (Joplin,Mo.) substantially conforming to a ISSA type III gradation. The mineralfiller was Portland cement at about 1% for all mixtures.

The fibers were Polyester fibers of 0.25-1 inch in length and variousdenier thicknesses.

No recycled materials were utilized but a typical Ralumac controladditive was used to control mixing and set times, and water was used toprovide sufficient fluidity to the mixture.

The composition was produced by mixing the Portland cement together withthe aggregate. The water and additives were added to the composition andsufficiently mixed. The asphalt emulsion was added to the composite atabout 13% based on the weight of the mixture. Finally, polyester fiberswere added and sufficiently mixed.

The resulting mixture was suitably poured into a mold of sufficient sizefor testing. The Texas Overlay tester was used to evaluate the samplesfollowing a variation on standard operating procedure TxDOT T-248-F. Thetesting included the following adjustments to the TxDOT T-248-F testprocedure as promulgated by the Texas Department of Transportation inMarch 2007:

2. Apparatus

-   -   2.1 Change the maximum displacement from 0.025 in to 0.05 in.        Change the cycle time from 10 seconds to 60 seconds.    -   2.2 Delete    -   2.4 Delete

4 Specimens

-   -   4.1 Replace with: “Laboratory Molded Specimens—Prepare specimens        according to ISSA TB-100 and TB-147. Specimens size should be 6        in. long by 3 in. wide by 0.5 in. tall”    -   4.2. Delete

5 Procedure

-   -   5.1 Delete    -   5.2 Delete    -   5.3 Delete the last paragraph    -   5.6 Change the constant temperature from 77±3° F. to 41±2° F.        Replace the third paragraph with: “Start the test by enabling        the start button in the program. Perform testing until the        maximum load measured is less than 10 pounds. If that is not        reach, run test to 1,200 cycles.”

6 Report

-   -   6.1 Delete “Percent decline in load”        The foregoing procedure is hereinafter referred to as the        “Modified TxDOT T-248-F” procedure. The following samples were        tested using the Modified TxDOT T-248-F procedure:

Sample A—control sample with 0% fibers

Sample B—0.05% based on the weight of the aggregate 0.25 inch fibers

Sample C—0.10% based on the weight of the aggregate 0.25 inch fibers

Sample D—0.10% based on the weight of the aggregate 0.50 inch fibers

Sample E—0.20% based on the weight of the aggregate 0.50 inch fibers

Test Data Shown in FIG. 1.

Any bituminous fiber mixture representing enhanced fatigue or crackresistance relative to the control is considered an object of thisinvention. Preferably, the Modified Texas Overlay Test is utilized andany bituminous fiber mixture exhibiting 3 or greater cycles to failureis considered to have improved fatigue or crack resistance of themixture; most preferably is any bituminous fiber mixture exhibiting 5 orgreater cycles to failure

From the above description, it is clear that the present invention iswell adapted to carry out the objects and to attain the advantagesmentioned herein as well as those inherent in the invention. Whilepresently preferred embodiments of the invention have been described forpurposes of this disclosure, it will be understood that numerous changesmay be made which will readily suggest themselves to those skilled inthe art and which are accomplished within the spirit of the inventiondisclosed and claimed.

1. A method of selecting a fiber modified layer for applying on anexisting surface, comprising the steps of: providing a binder mixturehaving an effective amount of an aggregate material, a binder, and aplurality of fibers, wherein each of the plurality of fibers has alength greater than 0.25 inches; applying the binder mixture to aselected surface to form a fiber modified proposed layer; testing thefiber modified proposed layer for fatigue or crack resistant propertieswhere testing the fiber modified proposed layer for fatigue or crackresistant properties comprises using a Texas Overlay test in accordancewith Modified TxDOT T-248-F; and selecting the binder mixture forapplication on the existing surface for performance if the fibermodified proposed layer has fatigue or crack resistant properties. 2.The method of claim 1 wherein the aggregate material is mineralaggregates, man made aggregates, recycled materials, or mixturesthereof.
 3. The method of claim 2 wherein the mineral aggregates aresand, stone, lime, Portland cement, kiln dust, or mixtures thereof. 4.The method of claim 2 wherein the man made aggregates are wet bottomboiler slag, blast furnace slag, or mixtures thereof.
 5. The method ofclaim 2 wherein the recycled materials are reclaimed asphalt pavement,glass, ground rubber tires, ceramics, metals, or mixtures thereof. 6.The method of claim 1 wherein the binder is an asphalt emulsion.
 7. Themethod of claim 6 wherein the asphalt emulsion is elastomer-modified. 8.The method of claim 6 wherein the asphalt emulsion is polymer modified.9. The method of claim 8 wherein the polymer is natural latex.
 10. Themethod of claim 8 wherein the polymer is SBR latex or neoprene latex.11. The method of claim 1 wherein the binder is an asphalt emulsion, hotasphalt cement, hot polymer modified asphalt cement, petroleum solventcutback asphalt, polymer modified petroleum solvent cutback asphalt,resinous hydrocarbons, emulsified resinous hydrocarbons, emulsifiedpolymer modified resinous hydrocarbons, or mixtures thereof.
 12. Themethod of claim 1 wherein the plurality of fibers is formed frompolyester.
 13. The method of claim 1 wherein the plurality of fibers issynthetic fiber, glass fiber, metallic fiber, steel fiber, boron fiber,aluminum fiber, acrylic fiber, nylon fiber, rayon fiber, polyesterfiber, polystyrene fiber, cellulose acetate fiber, acetate base fiber,polypropylene fiber, polyacrylamide fiber, polyethylene fiber, carbonfiber, aramid fiber, or mixtures thereof.
 14. The method of claim 1wherein each of the plurality of fibers has a length of at least 0.5inches.
 15. The method of claim 1 wherein the binder mixture furthercomprises one or more additives.
 16. The method of claim 15 wherein theadditives are adhesion promoters, surfactants, polymers, cross-linkingagents, vulcanization agents, accelerators, extenders, or fluxingagents.
 17. The method of claim 1 wherein the fiber modified proposedlayer has fatigue or crack resistant properties if the testing resultsin a number of cycles to failure greater than 3 where displacement is0.05 inches, cycle time is 60 seconds, and temperature is 5° Celsius.18. The method of claim 1 wherein testing the fiber modified proposedlayer for fatigue or crack resistant properties comprises usingflexibility tests, bending tests, or fracture energy and fracturetoughness tests.
 19. The method of claim 1 further comprising applyingthe selected fiber modified proposed layer having crack resistantproperties to the existing surface.
 20. The method of claim 19 whereinsaid existing surface has a direction of travel, further comprisingpreferentially aligning the plurality of fibers in the binder mixture inthe direction of travel.